In recent years, consumer demand for sport drinks has increased substantially. Sport drinks, particularly those using oxygenated liquid or even supersaturated oxygenated oxygen, have been gaining in popularity over carbonated soda. Some sport drinks add in minerals to alleviate symptoms of dehydration and to provide an aid to supply glucose for energy production. To provide the necessary oxygenated liquid for the sports drink, it may be necessary to supersaturate liquid, for example mineral water, to a level far exceeding the normal amount of oxygen from air separation. It is also necessary that the liquid be sterilized and sanitized for human consumption.
Work in the art has attempted to increase the equilibrium concentration of the oxygen in the water by lowering the temperature of the water and then pressurizing the oxygen and water in a contacting device using trays, in an effort to drive out the dissolved oxygen to a high equilibrium level. Pure oxygen is used. However, the maximum oxygen concentration has been measured only to about 50 mg/l.
It has been particularly difficult to attain high oxygen concentration in bottled water because prior research has been directed to making "equilibrated oxygen" water, not "supersaturated oxygen" water. Supersaturation, by definition, is an unsteady process in which more oxygen is dissolved than water can receive in equilibrium. If the contacting device can provide sufficient residence time and keep the oxygen gas pure, an equilibrium concentration can be approached, which is about 50 ppm at a chilled water temperature of 5.degree. C.
However, mineral water or any water from natural source contains certain amount of dissolved air. As air contains 79% nitrogen, the pure oxygen used by the prior art will strip out the nitrogen from the air, forming a mixture of less than 100% oxygen. Therefore, the water will be establishing equilibrium with a gas mixture instead of pure oxygen. With heat leaks and pipe friction, chilling and pressurizing the oxygen as in prior arts can only achieve a fraction of the desired equilibrium oxygen concentration.
Furthermore, bacteria removal from the water was carried out generally by reverse osmosis, which also provided an undesirable taste to the water. Ozonation is sometimes used by passing air through an ozone generator. Any unused ozone is vent off from the ozone contacting devices. In general, an adequate oxygen dissolution process and efficient sanitizing process are the results.
It is therefore desirable for a new process to produce supersaturated oxygenated liquid that will retard and prevent bacterial growth.